The Seemingly Intractable Ecological Responses of Invertebrates in North American Wetlands: A Review

Invertebrates play important ecological roles in wetlands, but what factors control their dynamics are poorly established. I review available research conducted in 14 areas of North America where invertebrates have received the most attention. Studies indicate that hydrology, plant factors, anthropogenic disturbance, and predation are the most important controls on wetland invertebrates, but little consensus emerged about how these factors influence invertebrate communities. Findings were often equivocal, contradictory, or inconclusive, either within or among areas. Considerable evidence indicated that wetland invertebrates are resilient, generalist organisms, and a lack of response may reflect insensitivity to environmental variation. However, numerous studies also indicated distinct responses by some invertebrates in some wetlands, although consistent patterns were often lacking. This suggests that wetland invertebrates might be very sensitive to environmental variation, but interactions can be complex and difficult to predict. Either conclusion means that generalizations about how invertebrates in wetland respond ecologically will be difficult to generate without careful study.